Portable radiographic film processing apparatus

ABSTRACT

A radiographic film processing apparatus for effecting the development of cassette-enclosed Poloroid type film packets having rupturable pads containing developing chemicals which are released by compression and spread over the exposed film. Rupturing of the pods and distribution of the enclosed chemicals is accomplished by a pair of driven rollers, the rotation of which is automatically stopped by a wedge mechanism which wedges between the rollers just prior to entry therebetween of the trailing edge of the film packet, thereby preventing fouling of the rollers by chemicals squeezed from the trailing edge of the film packet. The wedge mechanism is activated by the trailing edge of the film packet itself so that the apparatus operates properly regardless of the packet length.

United States Patent [191 Mather July 22, 1975 PORTABLE RADIOGRAPHICFILM PROCESSING APPARATUS [52] US. Cl 354/304; 354/86 [51] Int. Cl. G03D9/02 [58] Field of Search 354/304, 85, 86

[56] References Cited 1 UNITED STATES PATENTS Bachelder et al 354/304Erikson Land ..L t. 354/304 Primary Examiner-Richard L. Moses Attorney,Agent, or FirmRalph S. Branscomb 57 ABSTRACT A radiographic filmprocessing apparatus for effecting the development of cassette-enclosedPoloroid type film packets having rupturable pads containing developingchemicals which are released by compression and spread over the exposedfilm. Rupturing of the pods and distribution of the enclosed chemicalsis accomplished by a pair of driven rollers, the rotation of which isautomatically stopped by a wedge mechanism which wedges between therollers just prior to entry therebetween of the trailing edge of thefilm packet, thereby preventing fouling of the rollers by chemicalssqueezed from the trailing edge of the film packet. The wedge mechanismis activated by the trailing edge of the film packet itself so that theapparatus operates properly regardless of the packet length.

15 Claims, 10 Drawing Figures PATENTEDJUL22 ms 3 896,469

sum 1 1 44 Fig.2, '4 O 9 PATENHYD 3,896,469

sum 3 1 PORTABLE RADIOGRAPHIC FILM PROCESSING APPARATUS BACKGROUND OFTHE INVENTION 1. Field of the Invention .The invention relates toportable Polaroid type fil developing devices, and particularly thoseadapted for use in developing x-ray film in the field.

2. Description of Prior Art Cassette enclosed film packets containingphotosensitive film, a pring receiving sheet, and pods of a developingagent spaced therebetween, for example of the type disclosed in US. Pat.No. 2,726,337 are in wide use and utilize what is generally known as thePolaroid process. Development of these packets is effected by rupturingthe pods by the application of external pressure and spreading thedeveloping agent thereby released between the photographically exposedfilm and the print receiving sheet, whereby within a predetermined timeinterval an image is transferred from the former to the latter.

Portable developing devices for use with these film packets of the typeutilizing a pair of pressure-applying rollers have been developed andare represented in US. Pat. Nos. 3,364,834 and 3,411,423. Inherent inthe use of these devices is the problem of preventing the expulsion ofthe developing agent from the open trailing edge of the film packet andthe fouling of the rollers therewith as the film packet completes itspassage through the developer. Solutions to this problem to date havevariously involved the use of spacers associated with the trailing edgeof the film packet to separate the rollers prior to entry of thetrailing edge therebetween, and a complex cam mechanism whichautomatically separates the rollers upon completion of a pre-determinednumber of rotations gauged to the length of the film packet to beprocessed. Both of these methods have their drawbacks, the first beingtedious and the latter requiring complex, and therefore relatively heavyand expensive, cams, cam followers and resilient biasing means,thelatter method also being incapable of properly processing filmpackets of lengths other than that length for which the machine wasspecifically designed.

SUMMARY OF THE INVENTION As claimed, the processor utilizes twopressureapplying rollers, one mounted in each of two shellswhich arepivoted together to form an openable housing. Two collapsible armsextend from the front of the housing to hold a film cassette with theleading edge thereof inserted into a slot in the front of the housing.The tab of a film packet projecting from the leading edge of thecassette is engaged between the rollers, which are interengaged forsimultaneous rotation and preferably crank-driven. The rollers areoperated to draw the film packet therebetween, rupturing the developerchemical containing pods disposed near the front margin of the packetand spreading the chemicals throughout the film packet, the emergingpacket entering a light-tight bag having a zippered opening therein forremoval of the processed film packet. As the trailing edge of the packetnears the pressure line between the rollers, a stop means arrests themotion of the rollers to prevent expulsion and spillage of thedeveloping chemicals from the trailing edge. The stop means preferablycomprises a pair of spaced wedges biased between the rollers by afriction clutch riding on one of the rollers and operated by the passageof the trailing edge of the film packet beyond a station adjacent thepressure line between the rollers. The two shells are then opened torelease the processed film packet which can then be easily removed fromthe apparatus from the front or through the zippered opening in thedeveloping bag. The processor is simple, lightweight, inexpensivelyproduced, and can be used with equal facility for developing filmpackets of various sizes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of the filmprocessor;

FIG. 2 is a side elevation view of the processor with a film cassette'inplace;

FIG. 3 is an enlarged sectional view taken on line 33 of FIG. 2;

FIG. 4 is a sectional view taken on line 44 of FIG.

FIG. 5 is an enlarged sectional view taken on line 6-6 of FIG. 5; I

FIG. 6 is a sectional view taken on line 6-6 of FIG.

FIG. 7 is an enlarged sectional view taken on line 77 of FIG. 1;

FIG. 8 is a sectional view similar to FIG. 7, but with the unit open forinsertion of a cassette;

FIG. 9 is a sectional view similar to FIG. 7, but with the stop engaged;and

FIG. 10 is a sectional view taken on line ,10-10 of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT General description andoperation The processor includes a housing 1 1 having an upper shell 12and a lower shell 14 hinged together at opposite ends of the rear orexit side as indicated at 16, so that the housing has an open positionand a closed position as shown in FIG. 8 and 9 respectively. The frontedges of the shells are relieved along a major central portion thereofto define a rectangular entry slot 18 to accommodate the insertedleading edge of a radiographic film cassette, illustrateddiagrammatically at '20, in FIG. 7, 9, and 10, when the housing isclosed.

As illustrated in FIG. 7, the film cassette contains a film packet 22having a tab 24 which projects from the cassette prior to withdrawal ofthe film packet and exthereof, and smearing the developing agentcontained therein between the two layers of the film packet.

The film packets for which the unit is designed each have anintensifying screen sandwiched between the film and the print receivinglayer when the film is in the cassette. The intensifying screen remainsin the cassette as the film packet is withdrawn, so that the trailingedge 32 of the packet is necessarily open. To prevent the expulsion ofexcess developer agent from the open trailing edge, the apparatus isprovided with a stop means,

sensitive to the passage of the trailing edge beyond a point which willbe called the terminal station, which positively engages at least one ofthe rollers and arrests the motion of the rollers, just prior to entrytherebetween of the trailing edge.

Design ofthe stop meanscould include a number of various arrangements toengage one or both of the rollers and remain within the scope of theinvention as conceived but in the preferred embodiment it compriseswedges 34, a bearing 36, and a bias means comprising a friction clutch38, all carried on a bracket 40 pivotally mounted coaxially with thelower roller 28. The particular arrangement of these parts will be clearfrom the operation of the apparatus, which is as follows. In the openmode, best illustrated in FIG. 8, the stop means is inoperative, and thefriction clutch 38, which in the illustrated embodiment is a wire membershaped to conform with and frictionally contact a portion of the surfaceof the roller 14, defines a pair of lobes 42 on the sides thereof whichextend to a point immediately between the rollers as shown in FIG. 6. Inthis position, the wedges are clear of the rollers. When the leadingedge 20 of a film cassette is inserted into the slot 18, the tab 24 ofthe film packet contained therein lies between the rollers, straddled bythe wire lobes 42. When the upper shell 12 is closed and the rollers arerotated, as in FIG. 7, the clutch 38 rides on the lower roller, pivotingthe bracket 40 until the bearing 36 is brought into rolling contact withthe body of the film packet 22 as shown in FIG. 7. Being thus blockedfrom further rotation, the clutch slides on the roller 28 as the lattercontinues to rotate. Simultaneously, the film packet is drawn betweenthe rollers, the pods 30 are crushed, and the developing agent containedtherein is spread evenly throughout the film packet. Upon passage of thetrailing edge 32 beyond the terminal station, defined by the position ofthebearing 36, the stop means resumes its pivotal motion and the wedges34 are driven between the rollers as in FIG. 9, and further motion ofthe apparatus is prevented. The rollers can now be separated and theprocessed packet removed.

Other equally operable configurations of the stop means could beemployed. For example, biasing of the wedge could be accomplished by aspring or otherwise, or considerably modified without sacrificing itsfunction. The wedges 34 could be other than two and relocated,.andmounting of the entire stop assembly directly to the shell 14 ispossible.

Turning to other features of the invention and details of theconstruction, pivotally mounted to the opposite ends of the front of thelower shell 14 are two extending arms 44 which define, in their extendedposition illustrated in FIGS. 1 and 2, a cassette holding rack. Each armis provided at its distal end with a shoulder 46 which supports theouter end of the cassette substantially level with the forward end ofthe cassette when inserted into the slot 18. When not in use, the armsare pivotable inwardly, as shown in phantom in FIG. 1, to a compactposition adjacent the housing 10.

The front edge of each of the shells l2 and 14 is preferably provided,adjacent slot 18, with a pad 48 of L- shaped cross-sectional surface forengaging the leading edge of the cassette, each pod being maintained inposition by a backing plate 50 which is brazed or otherwise securedwithin its respective shell as illustrated. The pads are fabricated offelt, rubber, or other resilient material and are preferably dark incolor to aid in the exclusion of actinic light from the housing. Thepads are spaced from the rollers a pre-determined distance such that thetab projecting from the cassette inserted into the slot extends betweenthe rollers.

The rear of the housing is provided with an exit slot 52 between thehinges 16 through which the film packet emerges during processing, asseen in FIG. 9, and enclosing the exit slot from the outside is afilmreceiving container which is preferably in the form of a light-tightflexible developing bag 54 mounted to the rear of both of the housingshells by means of mounting plates 56 screwed or otherwise attachedthereto. The rear of the developing bag 54 may be provided with azippered opening 58 to facilitate removal of film packets receivedtherein. When a cassette is inserted into the entry slot 18 and thehousing is in its closed position and the zipper is closed, a completelylight-tight environment is provided for the film packet from the time itis withdrawn from the cassette until it is removed from the developingbag.

A lock mechanism, detailed in FIGS. 3 and 4, is provided for firmlysecuring the shells together in the closed position and comprises a bar60 axially pivoted to two studs 62 which are mounted at the extremeopposite ends of the upper shell 12. The bar has a pinbearing lip 64having oppositely projecting pins 66 which, when the bar is pivotedforwardly, engage in slots 68 provided in posts 70 which are upstandingfrom the lower shell 14. A flange 71 is provided along the length of thebar to facilitate manipulation of the lock.

The particular structural details of the rollers as disclosed herein arenot critical and are subject to modification. As illustrated in FIG. 5,each roller comprises a rigid inner cylinder 72 mounted on two hubs 74having projecting stub axles 76. Each of the cylinders 72 carries asecond, outer, cylinder 78, preferably composed of rubber or otherslightly resilient frictional material. The stub axles 76 of the upperroller 12 are journaled in bearing cups 80, which may be of vinyl, andthe bearing cups are received in elongated mounting sockets 82 in theend walls 84 of the upper shell. The bearing cups are biased away fromthe top of the upper shell by means of the spring-loaded plunger-tippedbolts 86 secured in threaded bores in the end walls 84. Thespring-loaded bolts enable the rollers to separate slightly in order toaccommodate the thickness of a film packet.

The lower roller 14 is journaled by one of its stubaxles in a thirdbearing cup 88 which is fixed in a cylindrical mounting socket 90 in oneof the end walls 92 of the lower shell. The other stub-axle is securedto a shaft 94 which extends through the opposite end wall 96 of thelower shell and is connected to a crank 98 by which the lower roller isdriven. The shaft may be prevented from frictionally engaging the endwall 96 by the use of a bushing or bearing inserted over the shaft.

In order to ensure more positive rotative correspondence between therollers, toothed bands 100 or other gear structures may be coactivelymounted at corresponding ends of the rollers, as shown in FIG. 10.

The apparatus as thus disclosed comprises a lightweight, portable filmprocessing apparatus which is collapsible into an extremely compact formand particularly adapted for use in the field. It is economicallymanufactured and performs its developing function with a minimum numberof parts and can be used to process film packets of any desired length.

I claim:

1. Improvements in combination with a film processing apparatus of thetype having a pair of opposed pressure-applying rollers in a housing foreffecting distribution of a processing agent between a pair ofliquidconfining layers of a film packet having a leading edge portion,an agent reservoir portion, a film accomodating portion, and a trailingedge portion, arranged in that order, said apparatus being adapted toreceive the leading edge portion and successive portions of said filmpacket sequentially in pressure-bearing relationship until said trailingedge portion passes a terminal station just short of the point of entrybetween said rollers, said improvements comprising:

means movable into physical engagement with at least one of said rollersto positively prevent continued motion thereof upon passage of saidtrailing edge beyond said terminal station and prior to entry of saidtrailing edge between said rollers whereby expulsion of the processingagent through said trailing edge portion is prevented.

2. Improvements according to claim 1 wherein said engaging meansincludes a wedge movably mounted in said housing and shiftable from afirst position clear of said rollers to a wedging position substantiallybetween said rollers to arrest the motion thereof.

3. The structure according to claim 2 wherein said wedge is duplicatedat the opposite ends of the rollers.

film packet at said terminal station to retain said wedge in said firstposition until the film packet has passed said station.

7. The structure according to claim 6 and including a bracket pivotallymounted coaxially with one of said rollers, said wedge, bias means andbearing element being mounted on said bracket.

8. Improvements according to claim 1 wherein said housing comprises anupper shell and a lower shell pivoted together such that said housinghas an open position and a closed position, one of said rollers beingmounted in each of said shells and so disposed therein as to receive inpressure applying relationship a film packet inserted therebetween whensaid housing is in the closed position, said rollers being separated insaid open position to allow removal of a processed film packet. i

9. Improvements according to claim 8 wherein said housing has an entryside with a longitudinal slot therein for receiving the forward endportion of a film cassette, and an exit side remote from said entry sideand having an exit opening therein for discharging a processed filmpacket emerging from between said rollers.

10. Improvements according to claim 9 and including a film cassetteholding rack mounted on the entry side of said housing adapted to hold afilm cassette with the forward edge portion thereof disposed in saidentry slot.

11. Improvements according to claim 10 wherein said rack comprises twoarms pivotally mounted to opposite ends of said housing and extendingoutward from the entry side thereof in parallel relationship when in useand pivotable to positions adjacent said housing for storage.

12. Improvements according to claim 9 and including a film packetreceiving container which is opaque to actinic light mounted on the exitside of said housing and enclosing said exit opening, said housing andcontainer, defining a light-tight enclosure with the leading edge of afilm cassette when the latter is inserted in said entry slot.

13. Improvements according to claim 12 wherein said container is aflexible bag foldable into compact form.

14. Improvements according to claim 13 wherein said flexible bag has azippered opening on a portion thereof remote from said housing wherebyaccess through said opening to processed film residing in said bag ispossible for removal thereof.

l5. Improvements according to claim 1 and including two toothed drivebands, one encircling and secured to each of said rollers at one endthereof for operatively and positively interengaging same forconcomitant rotation. 1 I

1. Improvements in combination with a film processing apparatus of thetype having a pair of opposed pressure-applying rollers in a housing foreffecting distribution of a processing agent between a pair ofliquid-confining layers of a film packet having a leading edge portion,an agent reservoir portion, a film accomodating portion, and a trailingedge portion, arranged in that order, said apparatus being adapted toreceive the leading edge portion and successive portions of said filmpacket sequentially in pressure-bearing relationship until said trailingedge portion passes a terminal station just short of the point of entrybetween said rollers, said improvements comprising: means movable intophysical engagement with at least one of said rollers to positivelyprevent continued motion thereof upon passage of said trailing edgebeyond said terminal station and prior to entry of said trailing edgebetween said rollers whereby expulsion of the processing agent throughsaid trailing edge portion is prevented.
 2. Improvements according toclaim 1 wherein said engaging means includes a wedge movably mounted insaid housing and shiftable from a first position clear of said rollersto a weDging position substantially between said rollers to arrest themotion thereof.
 3. The structure according to claim 2 wherein said wedgeis duplicated at the opposite ends of the rollers.
 4. Improvementsaccording to claim 2 wherein said engaging means includes a bias meansoperative during rotation of said rollers for biasing said wedge fromsaid first position toward said wedging position.
 5. Improvementsaccording to claim 4 wherein said bias means comprises a friction clutchcontacting one of said rollers and operatively connected with saidwedge.
 6. Improvements according to claim 4 wherein said stop meansincludes a bearing element engaging said film packet at said terminalstation to retain said wedge in said first position until the filmpacket has passed said station.
 7. The structure according to claim 6and including a bracket pivotally mounted coaxially with one of saidrollers, said wedge, bias means and bearing element being mounted onsaid bracket.
 8. Improvements according to claim 1 wherein said housingcomprises an upper shell and a lower shell pivoted together such thatsaid housing has an open position and a closed position, one of saidrollers being mounted in each of said shells and so disposed therein asto receive in pressure applying relationship a film packet insertedtherebetween when said housing is in the closed position, said rollersbeing separated in said open position to allow removal of a processedfilm packet.
 9. Improvements according to claim 8 wherein said housinghas an entry side with a longitudinal slot therein for receiving theforward end portion of a film cassette, and an exit side remote fromsaid entry side and having an exit opening therein for discharging aprocessed film packet emerging from between said rollers. 10.Improvements according to claim 9 and including a film cassette holdingrack mounted on the entry side of said housing adapted to hold a filmcassette with the forward edge portion thereof disposed in said entryslot.
 11. Improvements according to claim 10 wherein said rack comprisestwo arms pivotally mounted to opposite ends of said housing andextending outward from the entry side thereof in parallel relationshipwhen in use and pivotable to positions adjacent said housing forstorage.
 12. Improvements according to claim 9 and including a filmpacket receiving container which is opaque to actinic light mounted onthe exit side of said housing and enclosing said exit opening, saidhousing and container, defining a light-tight enclosure with the leadingedge of a film cassette when the latter is inserted in said entry slot.13. Improvements according to claim 12 wherein said container is aflexible bag foldable into compact form.
 14. Improvements according toclaim 13 wherein said flexible bag has a zippered opening on a portionthereof remote from said housing whereby access through said opening toprocessed film residing in said bag is possible for removal thereof. 15.Improvements according to claim 1 and including two toothed drive bands,one encircling and secured to each of said rollers at one end thereoffor operatively and positively interengaging same for concomitantrotation.